1. Field of the Invention
The present invention relates to a charging and discharging system, and more particularly, to a charging and discharging system including a vehicle having an electric storage device mounted thereon and a charging and discharging device charging and discharging the electric storage device and a vehicle used in the charging and discharging system.
2. Description of Related Art
In recent years, a charging device has been developed which converts commercial AC power into DC power and which supplies the DC power to an electric storage device of a vehicle such as an electric vehicle. Japanese Patent Application Publication No. 2012-70577 (JP 2012-70577 A) discloses a discharging device that converts DC power of an electric storage device of a vehicle into AC power and that supplies the AC power to a load.
However, when the charging device and the discharging device are individually provided, efficiency is poor and thus there is demand for development of a charging and discharging device capable of performing both charging and discharging of an electric storage device of a vehicle. When such a charging and discharging device is used, it is assumed that the same cable as in the related art is used. This cable includes a connector connected to an inlet of a vehicle, a fuse, and a power line. In the vehicle, a relay and a fuse are disposed between the inlet and the electric storage device (see FIG. 2A).
When the charging and discharging device and the inlet of the vehicle are connected to each other via the cable and the electric storage device is discharged, it is thought that a power line short-circuits and an overcurrent flows from the electric storage device into the short-circuited portion of the power line. When the fuse of the vehicle is not melted down but the relay is fixed to the ON state, and the fuse of the cable is melted down, a state may be maintained in which the voltage of the electric storage device is applied to the inlet of the vehicle (see FIG. 2B).